U.S. patent application number 11/723225 was filed with the patent office on 2007-09-20 for structure and method for stopping water in shielded electric wire.
This patent application is currently assigned to YAZAKI CORPORATION. Invention is credited to Shigemi Hashizawa, Hidehiro Ichikawa, Kouichi Yamamoto.
Application Number | 20070215374 11/723225 |
Document ID | / |
Family ID | 38071936 |
Filed Date | 2007-09-20 |
United States Patent
Application |
20070215374 |
Kind Code |
A1 |
Ichikawa; Hidehiro ; et
al. |
September 20, 2007 |
Structure and method for stopping water in shielded electric
wire
Abstract
To simply provide a water-stopping structures for shielded
electric wire in the shielded portion of the wire at a low cost, a
water stop structure in a shielded electric wire is comprised by
stripping a sheath 4 of the shielded electric wire in the middle
part thereof; permeating an adhesive into the exposed shield member
3; overlaying a heat shrinkable tube 12 over the shield member via
hot melt 14; and heat shrinking the heat shrinkable tube 12 in a
state where both ends of the heat shrinkable tube 12 are overlapped
with the outer periphery of the sheath 4.
Inventors: |
Ichikawa; Hidehiro;
(Shizuoka, JP) ; Yamamoto; Kouichi; (Shizuoka,
JP) ; Hashizawa; Shigemi; (Shizuoka, JP) |
Correspondence
Address: |
SUGHRUE-265550
2100 PENNSYLVANIA AVE. NW
WASHINGTON
DC
20037-3213
US
|
Assignee: |
YAZAKI CORPORATION
Minato-ku
JP
|
Family ID: |
38071936 |
Appl. No.: |
11/723225 |
Filed: |
March 19, 2007 |
Current U.S.
Class: |
174/75C |
Current CPC
Class: |
H01R 4/72 20130101; H01B
7/285 20130101; Y02A 30/14 20180101 |
Class at
Publication: |
174/075.00C |
International
Class: |
H01R 9/05 20060101
H01R009/05 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 17, 2006 |
JP |
P2006-073849 |
Claims
1. A water stop structure in a shielded electric wire, comprised
by: stripping a sheath of the shielded electric wire in the middle
part thereof; permeating an adhesive into the exposed shield
member; overlaying a heat shrinkable tube over the shield member
via hot melt; and heat shrinking the heat shrinkable tube in a
state where both ends of the heat shrinkable tube are overlapped
with the outer periphery of the sheath.
2. A method of water stop in a shielded electric wire, comprising
the steps of: stripping a sheath of the shielded electric wire in
the middle part; permeating an adhesive into a shielded electric
wire exposed by the middle stripping; overlaying a heat shrinkable
tube over the middle striped part via hot melt; overlapping both
ends of the heat shrinkable tube with an outer periphery of the
sheath; and heat shrinking the heat shrinkable tube.
3. The method according to claim 2, wherein the adhesive is
permeated into the shield member exposed by the middle stripping by
immersing the middle stripped part into the adhesive contained in a
container.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a structure and method for
stopping water in a shielded electric wire.
[0003] 2. Description of the Related Art
[0004] It is known that a structure for stopping water
infiltrations through the gaps inside the covering material in a
electric wire by permeating an adhesive having a flow ability into
the inside of the covering material which covers core of wire and
hardening the adhesive.
[0005] In this case, for example, as described in JP-A-2004-355851,
the adhesive is surely permeated into a wide area by supplying the
adhesive from one end of the electric wire and drawing out air from
the covering material from the other end of the electric wire.
[0006] However, in case of stopping water in the shielded electric
wire in which a shielding member (braid, metal foil, and networked
brace metal, etc.) surrounding the core at an inner side of an
outer shell (sheath) is arranged, the water stopping of the shield
member should be considered as well as the water stopping of the
core, but since an adhesive is simply applied onto the exposed part
of the shield member in the past, it is not possible to obtain
effective permeation of the adhesive into the shield member, and
sufficient water stopping ability may not be attained.
[0007] Meanwhile, a technique which draws out air from a terminal
other than the supplying side of the adhesive is proposed, but
there exist problems in that air drawing equipment is required, and
the operation is difficult, so it does not meet cost
conditions.
SUMMARY OF THE INVENTION
[0008] The invention has been made to solve the above problems and
an advantage to provide a structure and method for stopping water
in a shielded electric wire in a simple and reliable with low
cost.
[0009] A water stop structure in a shielded electric wire according
to a first aspect of the invention is comprised by stripping a
sheath of the shielded electric wire in the middle part thereof;
permeating an adhesive into the exposed shield member; overlaying a
heat shrinkable tube over the shield member via hot melt; and heat
shrinking the heat shrinkable tube in a state where both ends of
the heat shrinkable tube are overlapped with the outer periphery of
the sheath.
[0010] A method of water stop in a shielded electric wire according
to a second aspect of the invention includes stripping a sheath of
the shielded electric wire in the middle part; permeating an
adhesive into a shielded electric wire exposed by the middle
stripping; overlaying a heat shrinkable tube over the middle
striped part via hot melt; overlapping both ends of the heat
shrinkable tube with the outer periphery of the sheath; and heat
shrinking the heat shrinkable tube.
[0011] In a third aspect of the invention according to the second
aspect, the adhesive may be permeated into the shield member
exposed by the middle stripping by immersing the middle stripped
part into the adhesive contained in a container.
[0012] According to the first aspect of the invention, by the heat
shrinkage of the heat shrinkable tube, while applying a pressure,
since it is possible to permeate the adhesive into the shield
member and harden the adhesive, the sufficient application of
adhesive onto the required portions is possible. Moreover, since
the adhesive is hardened in a pressurized state, bonding is surely
performed. In particular, since it is possible to bury the gaps of
heat shrinkable tube with the shielded electric wire by the hot
melt, not only it is possible to permeate an adhesive uniformly
into the shield member, but also it is possible to reliably block
the water stopping part from the outside. As a result, water
stopping ability can be reliably ensured for a long time, and the
infiltrations of moistures through the shield member can be
blocked.
[0013] In addition, since the water stopping part is protected by
the heat shrinkable tube, it is possible to increase durability.
Moreover, since resistance to the thermal expansion due to the
temperature change or the external force is exhibited, it is
possible to avoid the shape collapse thereof by keeping the shape
of the hardening adhesive, and the handling of the shielded
electric wire is easily performed while maintaining high water stop
ability.
[0014] In addition, since it is only configured such that the heat
shrinkable tube is shrunken by the hot melt and the heat shrinkable
tube at the state where the exposed part (water stopping part) of
the shield member is covered, difficult water stopping process can
be performed with simple equipment. In addition, since the water
stopping is performed in the middle of the shield member,
cumbersome water stopping of the shield member by the connectors
installed at the terminal is not required.
[0015] According to the second aspect of the invention, since the
water stopping structures in the first aspect of the invention can
be easily obtained without using air drawing-out equipment of high
cost, it is also possible to obtain the effect of the first aspect
of the invention. In addition, it is possible to shorten the
hardening time of the adhesive in accordance with a kind of
adhesive when the temperature of the heat shrinkable tube
increases.
[0016] According to the third aspect of the invention, since the
infiltrations of the adhesive onto the shield member is performed
by permeating the stripped part into the adhesive contained in a
container, it is possible to apply sufficient amount of adhesives
onto the shield member for a short time with simple equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic view of an embodiment of the water
stop structure of the shielded electric wire of the present
invention, in which, FIG. 1a shows a cross sectional view on a
state before shrinking a heat shrinkable tube, and FIG. 1b shows a
cross sectional view on a state after the shrinking of the heat
shrinkable tube.
[0018] FIG. 2 is a detailed sectional view of the FIG. 1a.
[0019] FIG. 3 is a perspective view of the stripped portion of the
shielded electric wire.
[0020] FIGS. 4a and 4b are explanatory views of the water stop
structure of the shielded electric wire according to the embodiment
of the invention
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Hereinafter, embodiments of the invention will be described
with reference to the accompanying drawings.
[0022] FIG. 1 is a schematic view of an embodiment of the water
stop structure of the shielded electric wire, in which, FIG. 1a
shows a cross sectional view on a state before shrinking a heat
shrinkable tube, and FIG. 1b shows a cross sectional view on a
state after the shrinking of the heat shrinkable tube, FIG. 2 is a
detailed sectional view of the FIG. 1a, FIG. 3 is a perspective
view of the stripped portion of the shielded electric wire, and
FIGS. 4a and 4b are explanatory views of an embodiment of the water
stop structure of the shielded electric wire.
[0023] To obtain the water stopping structures of the embodiment,
at first, as shown in the FIG. 3, from the structures of shielded
electric wire, which comprising a core 1, an insulating layer 2, a
shield member 3 (braid, metal foil, and networked brace metal,
etc.), and a sheath 4 are arranged in this order, and the middle of
the sheath 4 is stripped (first step).
[0024] Next, as shown in the FIG. 1a, adhesive 10 with flow ability
is permeated into the shield member 3 exposed by stripping the
middle of the sheath (the second step). In addition, a heat
shrinkable tube 12 is overlay over the exposed part via hot melt
14, and both ends of the heat shrinkable tube 12 and the outer
periphery of the sheath 14 are overlapped and kept in this state
(the third step). Then, at this state, the heat shrinkable tube 12
is shrunken (the fourth step). For this reason, shrinkage of heat
shrinkable tube 12 is performed, and water stopping structure S is
obtained as shown in the FIG. 1b and FIG. 2.
[0025] At this time, for example, as shown in the FIG. 4a, in the
second step, since the middle stripped part A is immersed into the
adhesive 10 in a container 30, the adhesive 10 onto the exposed
part is permeated. Furthermore, as shown in the FIG. 4b, in the
fourth step, since the covered heat shrinkable tube 12 is located
under the heater 40, heat shrinkage of the heat shrinkable tube 12
is performed by maintaining the environment temperature to a
predetermined temperature.
[0026] In the water stop structures described above, as shown in
the FIG. 1b, while applying a pressure P by the heat shrinkage of
the heat shrinkable tube 12, since it is possible to harden the
adhesive 10 permeated into the shield member 3, the adhesives 10
can be applied sufficiently on the required portions. Moreover,
since the adhesive 10 is hardened at the state where the pressure
is applied, reliable bonding can be performed.
[0027] In particular, since it is possible to bury the gap between
the heat shrinkable tube 12 and the shielded electric wire W by the
hot melt 14, it is possible to permeate an adhesive 10 uniformly
into the shield member 3. At this time, it is also possible to
reliably block the water stopping part S from the outside. As a
result, since water stopping ability can be attained reliably for a
long time, the infiltrations of moistures through the shield member
can be blocked.
[0028] In addition, since the water stopping part S is protected by
the heat shrinkable tube 12, the durability can be increased. Since
resistance to the thermal expansion due to the temperature change
or the external force is exhibited by tightening of the heat
shrinkable tube 12, it is possible to keep the hardening shape of
the adhesive 10 and to avoid the shape collapse thereof.
Furthermore, while maintaining high water stop ability, the
handling of the shielded electric wire W is easily performed.
[0029] Furthermore, since it is only configured such that the heat
shrinkable tube 12 is shrunken by the hot melt 14 and the heat
shrinkable tube 12 at the state where the exposed part (water
stopping part) of the shield member 3 is covered, difficult water
stopping process can be performed with simple equipment without
using the prior art cost-high air drawing-out equipment. Therefore,
it is possible to prohibit the increase of cost. In addition, since
the water stopping is performed in the middle of the shield member
W, cumbersome water stopping of the shield member W by the
connectors installed at the terminal of the wire is not
required.
[0030] Furthermore, it is possible to shorten the hardening time of
the adhesive 10 when the temperature of the heat shrinkable tube 12
increases (at the time of heat shrinkage) in accordance with a kind
of adhesive. For example, in the case of adhesive of cyanoacrylate
series, after increasing the temperature up to 80.degree. C., and
the hardening can be performed within 1 hour. Moreover, in the case
where the infiltrations of the adhesive 10 onto the shield member 3
is performed by permeating the middle stripped part A into the
adhesive 10 in the container 30, it is possible to provide
sufficient amount of adhesives onto the shield member for a short
time with simple equipment.
[0031] Consequently, as shown in the FIGS. 4a and 4b, since an
adhesive is immersed within 0. 1 hour, the heat shrinkable tube 12
is shrunken within 0. 1 hour, and the adhesive is hardened within
1. 1 hour, it is possible to shorten the work time.
[0032] In addition, considering on the factors which affecting the
water stopping ability, it is preferable that repeat the
experiments and find out the best condition by the adjusting the
ratio of shrinkage, viscosity of the adhesive 10 or hot melt 14,
and other conditions (the width of the stripped off middle part and
amount of wrap (length of the heat shrinkable tube) etc.).
* * * * *